RC J1148+0455 identification: gravitational lens or group of galaxies ?

The structure of the radio source RC B1146+052 of the ``Cold'' catalogue is investigated by data of the MIT-GB-VLA survey at 4850 MHz. This source belongs to the steep spectrum radio sources subsample of the RC catalogue. Its spectral index is $\alpha$ = -1.04. The optical image of this source obtained with 6m telescope is analysed. The radio source center is situated in a group of 8 galaxies of about 24$^m$ in the R-filter. The possible explanations of the complex structure of radio components are considered.Comment: 6 pages, 5 figures, uses psfig.sty. This was the poster as presented on Gamow Memorial Internat. Conference GMIC'99 "Early Universe: Cosmological Problems and Instrumental Technologies" in St.Petersburg, 23-27 Aug., 1999. Submitted to Proceedings to be published in A&A Transaction

3,4,6-Tri-O-acetyl-2-(N-acetylacetamido )-1,2-dideoxy-o-Iyxohex- 1-enopyranose, an Acetamido-n-galactal Derivative, and the Mechanism of its Formation from 2-Acetamido-2-deoxy-D-galactose

The structure of an unsaturated amino sugar derivative, formed in low yield when 2-acetamido-2-deoxy-o-galactose _is treated with boiling isopropenyl acetate containing a trace of p-toluenesulfonic acid, and formulated as 1,4,6-tri-0-acetyl-2-(N-acetylacetamido)- 2,3-dideoxy-o-threo-hex-2-enopyranose(II) in an earlier publication, has been re-examined. Through a series of steps, including catalytic hydrogenation, the substance has been converted into a compound with an NMR spectrum which shows it to be 3,4,6-tri- 0-acetyl-2-(N -acetylbenzamido )-1,5-anhydro-2-deoxy-o-tali tol (X). This fact, together with a re-examination of its NMR spectrum, show the unsaturated compound to be 3,4,6-tri-0-acetyl-2-(N·· -acetylacetamido)-1,2-dideoxy-o-lyxo-hex-l-enopyranose (III), a derivative of 2-acetamido-o-galactal (VI). The yield of III from 2-acetamido-2-deoxy-o-galactose has been substantially improved through isolation of . 2-acetamido-1,3,4 , 6-tetra-0-acetyl-2-deoxy-~- o-galactopyranose (XIII) as an intermediate and III has been obtained in crystalline form. Evidence for the mechanism of its formation is presented

The Behavior of 2-Acetamido-2-deoxy-o-galactose with Isopropenyl Acetate in the Presence of p-Toluenesulfonic Acid. Formation of an Unsaturated Aminosugar Derivative

Treatment of 2-acetamido-2-deoxy-n-galactose (III) with isopropenyl acetate and p-toluenesulfonic acid gives 2-(n-glycero-1,2- -diacetoxyethyl)-4-(N-acetylacetamido) furan (II), the anomeric 1,3, 4,6-te tra-O-acety 1- 2-(N -acetylacetamido )-2-d eoxy-o-gala ctopyranoses (IV and V), a mixture of the anomeric 1,3,5,6-te tra-0-acetyl-2- -(N-acetylacetamido) -2- deoxy-o-galactofuranoses (VII) and 1,4,6 - -tri -O-acetyl-2-(N-acetylacetamido)-2 ,3-dideoxy-o-threo-hex-2-enopyranose (X) . The anomeric 2-acetamido-1,3,4,6 -tetra-O-acetyl-2- -deo xy-n-galactopyranoses (VI) were also d etected ; they may be primary products or artifacts arising from IV and V by spontaneous de-N-acetylation in the course of the chromatography w hich was used

3,4,6-Tri-O-acetyl-2-(N-acetylacetamido )-1,2-dideoxy-o-Iyxohex- 1-enopyranose, an Acetamido-n-galactal Derivative, and the Mechanism of its Formation from 2-Acetamido-2-deoxy-D-galactose

The structure of an unsaturated amino sugar derivative, formed in low yield when 2-acetamido-2-deoxy-o-galactose _is treated with boiling isopropenyl acetate containing a trace of p-toluenesulfonic acid, and formulated as 1,4,6-tri-0-acetyl-2-(N-acetylacetamido)- 2,3-dideoxy-o-threo-hex-2-enopyranose(II) in an earlier publication, has been re-examined. Through a series of steps, including catalytic hydrogenation, the substance has been converted into a compound with an NMR spectrum which shows it to be 3,4,6-tri- 0-acetyl-2-(N -acetylbenzamido )-1,5-anhydro-2-deoxy-o-tali tol (X). This fact, together with a re-examination of its NMR spectrum, show the unsaturated compound to be 3,4,6-tri-0-acetyl-2-(N·· -acetylacetamido)-1,2-dideoxy-o-lyxo-hex-l-enopyranose (III), a derivative of 2-acetamido-o-galactal (VI). The yield of III from 2-acetamido-2-deoxy-o-galactose has been substantially improved through isolation of . 2-acetamido-1,3,4 , 6-tetra-0-acetyl-2-deoxy-~- o-galactopyranose (XIII) as an intermediate and III has been obtained in crystalline form. Evidence for the mechanism of its formation is presented

A dispersive wave pattern on Jupiter's fastest retrograde jet at 20∘20^\circS

A compact wave pattern has been identified on Jupiter's fastest retrograding jet at 20S (the SEBs) on the southern edge of the South Equatorial Belt. The wave has been identified in both reflected sunlight from amateur observations between 2010 and 2015, thermal infrared imaging from the Very Large Telescope and near infrared imaging from the Infrared Telescope Facility. The wave pattern is present when the SEB is relatively quiescent and lacking large-scale disturbances, and is particularly notable when the belt has undergone a fade (whitening). It is generally not present when the SEB exhibits its usual large-scale convective activity ('rifts'). Tracking of the wave pattern and associated white ovals on its southern edge over several epochs have permitted a measure of the dispersion relationship, showing a strong correlation between the phase speed (-43.2 to -21.2 m/s) and the longitudinal wavelength, which varied from 4.4-10.0 deg. longitude over the course of the observations. Infrared imaging sensing low pressures in the upper troposphere suggest that the wave is confined to near the cloud tops. The wave is moving westward at a phase speed slower (i.e., less negative) than the peak retrograde wind speed (-62 m/s), and is therefore moving east with respect to the SEBs jet peak. Unlike the retrograde NEBn jet near 17N, which is a location of strong vertical wind shear that sometimes hosts Rossby wave activity, the SEBs jet remains retrograde throughout the upper troposphere, suggesting the SEBs pattern cannot be interpreted as a classical Rossby wave. Cassini-derived windspeeds and temperatures reveal that the vorticity gradient is dominated by the baroclinic term and becomes negative (changes sign) in a region near the cloud-top level (400-700 mbar) associated with the SEBs, suggesting a baroclinic origin for this meandering wave pattern. [Abr]Comment: 19 pages, 11 figures, article accepted for publication in Icaru

Allylic Displacement Reactions of a 2-Acetamido-D-glucal Derivative with Acids and Phenols

Fusion of 3,4,6-tri-O-acetyl-2-(N-acetylacetamido)-1,2-dideoxy- o-arabino-hex-1-enopyranose [I, 2-(N-acetylacetamido)-o-glucal triacetate] with various acids and phenols in the presence of. a trace of p-toluenesulfonic acid causes loss of the acetoxy group at C-3, shift of the double bond to the C-2-C-3 position, and entry of an acyloxy or aryloxy group at C-1 to give esters and glycosides, respectively, of 4,6-di-0-acetyl-2-(N-acetylacetamido)-2,3-dideoxy- a-o-erythro-hex-2-enopyranose (compounds III, V, VI, and VII). In each case, the main product is accompanied by 1,4,6-tri-O- acetyl-2- (N-acetylacetamido) -2,3-dideoxy-a-o-erythro-hex-2-enopyranose (IV), a substance which is found to be readily accessible through the deliberate rearrangement of I under acidic conditions. While IV reacts with benzoic acid when boiled in benzene solution containing hydrogen chloride, I is recovered unchanged after treatment in this fashion. On the basis of these facts, a mechanism for the acid-catalyzed reaction of I with carboxylic acids and phenols is proposed. An improved preparation of I from 2-acetamido-2-deoxy-omannose via 2-acetamido-1,3,4,6-tetra-O-acetyl-2-deoxy-a-o-mannopyranose (II) is described. Phenyl 4,6-di-0-acetyl-2-(N -acetylacetamido )-2,3-dideoxy-a-D- eryth ro-hex-2-enopyranoside (VI) may be reduced by catalytic hydrogenation to the corresponding cyclohexyl glycoside (VIII), the double bond remaining unaffected

The Rearrangement Reaction of Some Acetylated Unsaturated 2-Acetamidoaldose Derivatives. Selective Removal of one N-Acetyl Group from 2-(N-acetylacetamido) Compounds

Two pairs of anomers, the l ,4,6-tri-0-acetyl-2-(N-acetylacetamido)- 2,3-dideoxy-o-hex-2-enopyranoses of the erythro- (II and III) and the threo- series (IV and VI) have been prepared and character; ized. The molecular conformation of these substances has been discussed on the basis of their NMR spectral characteristics. It is suggested that the a-anomers II and IV adopt the H~ conformation as the favorable one, while the B-anomers III and VI most probably tend to take a slightly modified H~ conformation. A convenient preparative method for selective removal of one N-acetyl group from 0-acetylated N-acetylacetamido compounds is described. The reaction can be carried out in aqueous dioxane solution at room temperature in the presence of an ammonium salt at pH ca. 9

Allylic Displacement Reactions of a 2-Acetamido-D-glucal Derivative with Acids and Phenols

Fusion of 3,4,6-tri-O-acetyl-2-(N-acetylacetamido)-1,2-dideoxy- o-arabino-hex-1-enopyranose [I, 2-(N-acetylacetamido)-o-glucal triacetate] with various acids and phenols in the presence of. a trace of p-toluenesulfonic acid causes loss of the acetoxy group at C-3, shift of the double bond to the C-2-C-3 position, and entry of an acyloxy or aryloxy group at C-1 to give esters and glycosides, respectively, of 4,6-di-0-acetyl-2-(N-acetylacetamido)-2,3-dideoxy- a-o-erythro-hex-2-enopyranose (compounds III, V, VI, and VII). In each case, the main product is accompanied by 1,4,6-tri-O- acetyl-2- (N-acetylacetamido) -2,3-dideoxy-a-o-erythro-hex-2-enopyranose (IV), a substance which is found to be readily accessible through the deliberate rearrangement of I under acidic conditions. While IV reacts with benzoic acid when boiled in benzene solution containing hydrogen chloride, I is recovered unchanged after treatment in this fashion. On the basis of these facts, a mechanism for the acid-catalyzed reaction of I with carboxylic acids and phenols is proposed. An improved preparation of I from 2-acetamido-2-deoxy-omannose via 2-acetamido-1,3,4,6-tetra-O-acetyl-2-deoxy-a-o-mannopyranose (II) is described. Phenyl 4,6-di-0-acetyl-2-(N -acetylacetamido )-2,3-dideoxy-a-D- eryth ro-hex-2-enopyranoside (VI) may be reduced by catalytic hydrogenation to the corresponding cyclohexyl glycoside (VIII), the double bond remaining unaffected

The Rearrangement Reaction of Some Acetylated Unsaturated 2-Acetamidoaldose Derivatives. Selective Removal of one N-Acetyl Group from 2-(N-acetylacetamido) Compounds

Two pairs of anomers, the l ,4,6-tri-0-acetyl-2-(N-acetylacetamido)- 2,3-dideoxy-o-hex-2-enopyranoses of the erythro- (II and III) and the threo- series (IV and VI) have been prepared and character; ized. The molecular conformation of these substances has been discussed on the basis of their NMR spectral characteristics. It is suggested that the a-anomers II and IV adopt the H~ conformation as the favorable one, while the B-anomers III and VI most probably tend to take a slightly modified H~ conformation. A convenient preparative method for selective removal of one N-acetyl group from 0-acetylated N-acetylacetamido compounds is described. The reaction can be carried out in aqueous dioxane solution at room temperature in the presence of an ammonium salt at pH ca. 9

The Physicist's Guide to the Orchestra

An experimental study of strings, woodwinds (organ pipe, flute, clarinet, saxophone and recorder), and the voice was undertaken to illustrate the basic principles of sound production in music instruments. The setup used is simple and consists of common laboratory equipment. Although the canonical examples (standing wave on a string, in an open and closed pipe) are easily reproduced, they fail to explain the majority of the measurements. The reasons for these deviations are outlined and discussed.Comment: 11 pages, 10 figures (jpg files). Submitted to European Journal of Physic